SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38810abcfd64434572e50270d6756347265fd6b578e01e27cdbe5fe8efe9ad49' 
  AND token = 'qNelheNY56vpX2tVqhHgknoLAvXbMsV3Vv06beeeMPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}